Lifting-jack.



No. 767,535. I PATENTED AUG. 16, 1904.

G. WIDEMAN.

LIPT-ING JACK.

APPLIOATION FILED NOV. 23, 1903.

N0 MODEL.

Wz'trz ease/54' [7 1/ 672 for? UNITED STATES Patented August 16, 1904.

PATENT OFFICE.

LIFTINGJACK.

SPECIFICATION formingpart of Letters Patent No. 767,535, dated August16, 1904,

Application filed November 23, 1903. Serial No. 182,273. (No model.)

To all whmn it may concern:

Be it known that I, GUsTAvUs WVIDEMAN, a citizen of the United States,residing at Aurora, in the county of Kane and State of Illinois, haveinvented certain new and useful Improvements in Lifting-Jacks, of whichthe following is a specification.

My invention relates to improvements in that class of lifting-jaeksinwhich the liftingbar moves in vertical planes, power being appliedthereto through a pivoted lever having a portion or connection thatdirectly engages the said lifting-bar.

The primary object is to produce an effective and durable device withmaximum economy in material and construction.

In the accompanying drawings, which form a part of this application,Figure 1 is a perspective view of a complete jack in inoperativeposition. Fig. 2 is a sectional view showing the relative positions oflifting-bar and lever when the former is being raised; and Fig. 3 is aview similar to Fig. 2, but showing the bar raised and locked in suchposition.

Referring to the details of the drawings, A represents a'rectangularpiece of metal of 'sufficient size and suitable material to form asubstantial base for the jack. Secured to the base by rivets Z) are twocomplementary metal plates B, which are connected with a spacetherebetween by rivets 6 have their lower edges flanged and perforatedto admit therivets Z), and constitute the standard of the jack.

Slidably mounted between the plates B is the lifting-bar O, which inthis instance is formed of two metal bars arranged with a slight spacetherebetween and suitably riveted together. In the rear edge of the barso formed notches c are provided, which are adapted to engage theprojecting ends of the pin (11, which is fixed in the rear side of thestirrup D. This stirrup is a piece of flat metal of the shape shown, isslidably arranged between the two parts of the bar (1, and is held inposition by the frictional engagement of the pins d d with the notchedand plain edges of said bar. The stirrup may be freely moved by hand toany point along the bar 0, and when released the rear pin d will becaused to enter one of the notches c by the dropping of the extendedportion of the stirrup on the opposite side of the bar C.

Rigidly secured to the lower portion of the lifting-bar is a rack-bar G,the rounded teeth of which are formed along its rear edge. Below theteeth the bar is cut out to provide a concave portion, as at g, for apurpose to be described.

Pivoted on the standard B is a cam E, which is provided on a part of itsperiphery with teeth 6 and adjacent to the teeth with a convex. orrounded portion 0 to which latter portion the cam pivotal point iseccentric. This cam is preferably a malleable-iron casting and is formedwith a socket a (shown by dotted lines,) into which is fitted andsecured by rivets the lower end of the lever F, by which the cam isoperated.

The stirrup being adjusted to the axle or other object to be raised andthe lever being in its vertical position, depressing the lever willraise the lifting-bar through the engagement between the teeth of thebar and the cam, and upon continuing the downward movement of the leverthe convex face 6 of the cam will be pressed against the concave face gof the rack-bar, thereby wedging the rack-bar between the rivets b andthe cam and preventing the downward movement of the lifting-bar. Theholding power of the cam is further augmented by the fact that thestress of the load carried by the lifting-bar is below the pivot-pointof the cam when the lever is depressed the full limit.

It will be apparent that the rack-bar may be integral with thelifting-bar instead of a separate piece and that the cam may be withouta socket and riveted to the lever or made integral therewith.

Novelty is not claimed for the stirrup, as it is understood to be awell-known feature of lifting-jacks in general use.

Having thus described my invention, what I claim as new, and desire toobtain by Letters Patent, is

1. In a lifting-jack, a standard having a slideway therein, alifting-bar slidably mountalong one edge and with a concave portion, a

cam pivoted in said base and rovided with the rivets, said cam andliftin -bar having cop a u o acting and intermeshing portlons adapted toteeth adapted to mesh with the teethof the lifting-bar, and alsoprovided with a convex portion adapted to engage the concave portion ofthe lifting-bar, and means for operating said cam.

2. In a lifting-jack, a standard composed of two plates secured togetherby rivets and with a space therebetween forming a slideway, a campivoted between said plates at one side of said slideway, and alifting-bar ar' ranged in said slideway between the cam and lift the barwhen the cam is operated, and also having portions in frictional contactadapted to lock the bar when the cam is operated in the mannerdescribed. I

In testimony whereof I aflix my signature in presence of two witnesses.

GUSTAVUS WIDEMAN. Witnesses:

W. H. FITCH, F. BENJAMIN

